Entities such as pharmaceutical companies and university research labs commonly use vacuum filtration sterilization of biological fluids such as cell culture media and buffer solutions. This typically involves what are referred to as bottle-top filters such as the three-piece example shown in FIG. 1. A bottle-top filter device 10 includes an upper unfiltered sample reservoir 11, which is removable and disposable. On the bottom there is a filtrate storage bottle 13 for collecting the liquid filtrate and a vacuum collar 14 with a vacuum port for manual coupling of a vacuum source in between reservoir 11 and storage bottle 13. Vacuum is applied downstream of the filter 12 to create a pressure differential, which draws the sample liquid through the filter into storage bottle 13. The neck of storage bottle 13 may be adapted to receive a cap to close the bottle after filtering is complete and the bottle is disconnected from vacuum collar 14. The components used in the sterilization process are normally sold pre-sterilized.
However, such components and the associated processes have various inherent challenges. For example, potential spills are a significant concern. A spill can disrupt production for up to an entire day and require use of a sanitizing laminar hood. Such spills may occur at any point throughout the filtration process, including after the filtration is complete and the filtrate storage bottle is being handled during further associated tasks.
In addition to the risk of spills and contamination, there are other problems with existing filtration products, particularly with the filtrate storage components. Some of the problems may include difficulties in handling a storage bottle, especially when the bottle is slippery as may be the case when one is removed from a water bath, trouble reading or providing adequate packaging information, and/or storage bottle caps cracking when tightened.